Transamidation‐based vitrimers from renewable sources

Abstract

Vitrimers are polymeric materials that behave as thermosets at room temperature but, when heated, they exhibit a plastic flow similar to thermoplastics, enabling their reprocessability. A series of new bio-based polyamide-polyamine vitrimers are synthetized starting from tris(2-aminoethyl)amine and epoxidized methyl oleate, a material that can be easily prepared from renewable resources obtainable both from natural products and waste. The incorporation of free amine groups in the network enables the transamidation exchange reaction with the crosslinking amide functions; this reaction, if appropriately catalyzed, donates a full reprocessability to the material. Boric acid, which is known to be a green, cheap and non-toxic catalyst for transamidation reactions, is employed in this work. Once that the optimal condition for the transamidation reaction is found, different catalyst loadings are tested and the obtained materials are subjected to thermal and mechanical characterization. The obtained materials possess good thermal stability up to 300 C and a T g value ranging between 7 and 21 C depending on the B(OH) 3 content. Furthermore it is possible to

Transamidation vitrimers enabled by neighbouring fluorine atom activation

“…43 In contrast to these dissociative CANs, transamidation vitrimers prepared from renewable resources were recently reported and presumed to involve an exchange between an amide and a free amine promoted by a boric acid catalyst. 80 Mechanistic considerations were not discussed in this study but the exchange seemed to occur through an associative pathway, in opposition to the previously reported dissociative CANs proceeding through the imide formation.…”

Self‐healing polymers for aviation applications and their impact on circular economy

“…Luca Pettazzoni et al have reported vitrimer utilizing transamidation chemistry using biobased sources. 94 The researchers have utilized waste vegetable oil, sunflower oil, and so forth, which are rich in triglyceride to obtain oleioc acid. Epoxidized methyl oleate crosslinked with tris(2-aminoethyl)amine has been used to obtain polyamide-polyamine vitrimer.…”

Self-healing polymers for surface scratch regeneration

“…30 In the transamidation self-healing mechanism, the reaction between amide linkages and free amines forms reversible amide adducts. 47 These adducts hence act as reversible crosslinks that can be broken and reformed, allowing the material to heal itself.…”